talos-op-linux/drivers/xen/tmem.c, branch master

xen: remove tmem driver

2019-07-17T06:09:58+00:00

The Xen tmem (transcendent memory) driver can be removed, as the related Xen hypervisor feature never made it past the "experimental" state and will be removed in future Xen versions (>= 4.13). The xen-selfballoon driver depends on tmem, so it can be removed, too. Signed-off-by: Juergen Gross Acked-by: Boris Ostrovsky Signed-off-by: Juergen Gross

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

mm, swap, frontswap: fix THP swap if frontswap enabled

2018-02-21T23:35:43+00:00

It was reported by Sergey Senozhatsky that if THP (Transparent Huge Page) and frontswap (via zswap) are both enabled, when memory goes low so that swap is triggered, segfault and memory corruption will occur in random user space applications as follow, kernel: urxvt[338]: segfault at 20 ip 00007fc08889ae0d sp 00007ffc73a7fc40 error 6 in libc-2.26.so[7fc08881a000+1ae000] #0 0x00007fc08889ae0d _int_malloc (libc.so.6) #1 0x00007fc08889c2f3 malloc (libc.so.6) #2 0x0000560e6004bff7 _Z14rxvt_wcstoutf8PKwi (urxvt) #3 0x0000560e6005e75c n/a (urxvt) #4 0x0000560e6007d9f1 _ZN16rxvt_perl_interp6invokeEP9rxvt_term9hook_typez (urxvt) #5 0x0000560e6003d988 _ZN9rxvt_term9cmd_parseEv (urxvt) #6 0x0000560e60042804 _ZN9rxvt_term6pty_cbERN2ev2ioEi (urxvt) #7 0x0000560e6005c10f _Z17ev_invoke_pendingv (urxvt) #8 0x0000560e6005cb55 ev_run (urxvt) #9 0x0000560e6003b9b9 main (urxvt) #10 0x00007fc08883af4a __libc_start_main (libc.so.6) #11 0x0000560e6003f9da _start (urxvt) After bisection, it was found the first bad commit is bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped out"). The root cause is as follows: When the pages are written to swap device during swapping out in swap_writepage(), zswap (fontswap) is tried to compress the pages to improve performance. But zswap (frontswap) will treat THP as a normal page, so only the head page is saved. After swapping in, tail pages will not be restored to their original contents, causing memory corruption in the applications. This is fixed by refusing to save page in the frontswap store functions if the page is a THP. So that the THP will be swapped out to swap device. Another choice is to split THP if frontswap is enabled. But it is found that the frontswap enabling isn't flexible. For example, if CONFIG_ZSWAP=y (cannot be module), frontswap will be enabled even if zswap itself isn't enabled. Frontswap has multiple backends, to make it easy for one backend to enable THP support, the THP checking is put in backend frontswap store functions instead of the general interfaces. Link: http://lkml.kernel.org/r/20180209084947.22749-1-ying.huang@intel.com Fixes: bd4c82c22c367e068 ("mm, THP, swap: delay splitting THP after swapped out") Signed-off-by: "Huang, Ying" Reported-by: Sergey Senozhatsky Tested-by: Sergey Senozhatsky Suggested-by: Minchan Kim [put THP checking in backend] Cc: Konrad Rzeszutek Wilk Cc: Dan Streetman Cc: Seth Jennings Cc: Tetsuo Handa Cc: Shaohua Li Cc: Michal Hocko Cc: Johannes Weiner Cc: Mel Gorman Cc: Shakeel Butt Cc: Boris Ostrovsky Cc: Juergen Gross Cc: [4.14] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: switch ->s_uuid to uuid_t

2017-06-05T14:59:12+00:00

For some file systems we still memcpy into it, but in various places this already allows us to use the proper uuid helpers. More to come.. Signed-off-by: Christoph Hellwig Reviewed-by: Amir Goldstein Acked-by: Mimi Zohar (Changes to IMA/EVM) Reviewed-by: Andy Shevchenko

cleancache: constify cleancache_ops structure

2016-01-27T14:09:57+00:00

The cleancache_ops structure is never modified, so declare it as const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: Konrad Rzeszutek Wilk

xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn

2015-09-08T17:03:52+00:00

All the caller of xen_tmem_{get,put}_page have a struct page * in hand and call pfn_to_gfn for the only benefits of these 2 functions. Rather than passing the pfn in parameter, pass directly the page and use directly xen_page_to_gfn. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel

xen: Use correctly the Xen memory terminologies

2015-09-08T17:03:49+00:00

Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN is meant, I suspect this is because the first support for Xen was for PV. This resulted in some misimplementation of helpers on ARM and confused developers about the expected behavior. For instance, with pfn_to_mfn, we expect to get an MFN based on the name. Although, if we look at the implementation on x86, it's returning a GFN. For clarity and avoid new confusion, replace any reference to mfn with gfn in any helpers used by PV drivers. The x86 code will still keep some reference of pfn_to_mfn which may be used by all kind of guests No changes as been made in the hypercall field, even though they may be invalid, in order to keep the same as the defintion in xen repo. Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a name to close to the KVM function gfn_to_page. Take also the opportunity to simplify simple construction such as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up will come in follow-up patches. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini Acked-by: Dmitry Torokhov Acked-by: Wei Liu Signed-off-by: David Vrabel

Merge tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2015-07-01T18:53:46+00:00

Pull xen updates from David Vrabel: "Xen features and cleanups for 4.2-rc0: - add "make xenconfig" to assist in generating configs for Xen guests - preparatory cleanups necessary for supporting 64 KiB pages in ARM guests - automatically use hvc0 as the default console in ARM guests" * tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: block/xen-blkback: s/nr_pages/nr_segs/ block/xen-blkfront: Remove invalid comment block/xen-blkfront: Remove unused macro MAXIMUM_OUTSTANDING_BLOCK_REQS arm/xen: Drop duplicate define mfn_to_virt xen/grant-table: Remove unused macro SPP xen/xenbus: client: Fix call of virt_to_mfn in xenbus_grant_ring xen: Include xen/page.h rather than asm/xen/page.h kconfig: add xenconfig defconfig helper kconfig: clarify kvmconfig is for kvm xen/pcifront: Remove usage of struct timeval xen/tmem: use BUILD_BUG_ON() in favor of BUG_ON() hvc_xen: avoid uninitialized variable warning xenbus: avoid uninitialized variable warning xen/arm: allow console=hvc0 to be omitted for guests arm,arm64/xen: move Xen initialization earlier arm/xen: Correctly check if the event channel interrupt is present

frontswap: allow multiple backends

2015-06-25T00:49:45+00:00

Change frontswap single pointer to a singly linked list of frontswap implementations. Update Xen tmem implementation as register no longer returns anything. Frontswap only keeps track of a single implementation; any implementation that registers second (or later) will replace the previously registered implementation, and gets a pointer to the previous implementation that the new implementation is expected to pass all frontswap functions to if it can't handle the function itself. However that method doesn't really make much sense, as passing that work on to every implementation adds unnecessary work to implementations; instead, frontswap should simply keep a list of all registered implementations and try each implementation for any function. Most importantly, neither of the two currently existing frontswap implementations in the kernel actually do anything with any previous frontswap implementation that they replace when registering. This allows frontswap to successfully manage multiple implementations by keeping a list of them all. Signed-off-by: Dan Streetman Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: David Vrabel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

xen: Include xen/page.h rather than asm/xen/page.h

2015-06-17T15:14:18+00:00

Using xen/page.h will be necessary later for using common xen page helpers. As xen/page.h already include asm/xen/page.h, always use the later. Signed-off-by: Julien Grall Reviewed-by: David Vrabel Cc: Stefano Stabellini Cc: Ian Campbell Cc: Wei Liu Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: netdev@vger.kernel.org Signed-off-by: David Vrabel